What a dramatic and scary night. It happened at one of america's biggest malls, not far from here, in suburban new jersey. Aerial pictures of the garden state plaza mall. Investigators on the scene. Around 9:30 last night, a 20-year-old man walked in and calmly began shooting. There were thousands of people inside that large mall. Hundreds remained all night during a lockdown, yard-by-yard search of the complex. Police calling it a nightmare scenario. Incredible night. We're going to get to the scene right now and talk to an eyewitness in a minute. Let's get to gio benitez. He's in paramus, new jersey, right now. Good morning, gio. Reporter: You said it. It was a frightening scene here overnight. A six-hour search for that gunman. The good news right now, nobody else was injured here. But that gunman was found dead. At approximately 9:20 p.M., A man wearing all-black and a motorcycle helmet opened fire with a modified large rifle at the garden state plaza mall in paramus, new jersey. As soon as I came upstairs, the mall security guy screamsiing at me to get out. Reporter: Panicked shoppers and mall employees ran for their lives. Thousands of people inside at the time. The man continued to shoot at an open area of the mall, not taking aim at anyone. They looked scared. And I saw him walking. I was like, oh, my god. Reporter: A massive police presence descended on new jersey's largest mall. Employees and shoppers, desperately seeking safety wherever they could. After the initial evacuation, 400 people remain hidden in that mall, as the gunman continued to fire. People were running crazy. We heard like three or four shooting. I think he was shooting some of the cameras in the mall. Reporter: S.W.A.T. Teams and canine units went store-to-store, searching for that shooter. At 3:20 a.M., Police see the suspect go to a secluded part of the mall and kill himself. No one else is injured. At 4:45 a.M., Police announce the all-clear, that the suspect 20-year-old richard shoop of new jersey shot at least six rounds in total from a rifle that he stole from his brother. I do not believe that mr. Shoop thought that he would come out of here this evening alive. He did have opportunity to shoot people and did not. Reporter: Law enforcement is familiar with shoop, who is known for having a drug problem. Using heroin and molly, a highly-potent form of ecstasy. And police say he left behind a note. The alleged shooter left behind a note. They're trying to figure out what happened here. Investigators are talking to his parents and brother and searching that home, george.

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